Medicine (Austin & Northern Health) - Research Publications
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ItemCoagulation abnormalities, bleeding, thrombosis, and management of patients with acute liver failure in Australia and New Zealand(WILEY, 2020-05)BACKGROUND AND AIM: To study the management of coagulation and hematological derangements among severe acute liver failure (ALF) patients in Australia and New Zealand liver transplant intensive care units (ICUs). METHODS: Analysis of key baseline characteristics, etiology, coagulation and hematological tests, use of blood products, thrombotic complications, and clinical outcomes during the first ICU week. RESULTS: We studied 62 ALF patients. The first day median peak international normalized ratio was 5.5 (inter-quartile range [IQR] 3.8-8.7), median longest activated partial thromboplastin time was 62 s (IQR 44-87), and median lowest fibrinogen was 1.1 (IQR 0.8-1.6) g/L. Fibrinogen was only measured in 85% of patients, which was less than other tests (P < 0.0001). Median initial lowest platelet count was 83 (IQR 41-122) × 109 /L. Overall, 58% of patients received fresh frozen plasma, 40% cryoprecipitate, 35% platelets, and 15% prothrombin complex concentrate. Patients with bleeding complications (19%) had more severe overall hypofibrinogenemia and thrombocytopenia. Thrombotic complications were less common (10% of patients), were not associated with consistent patterns of abnormal hemostasis, and were not immediately preceded by clotting factor administration and half occurred only after liver transplantation surgery. CONCLUSION: In ALF patients admitted to dedicated Australia and New Zealand ICUs, fibrinogen was measured less frequently than other coagulation parameters but, together with platelets, appeared more relevant to bleeding risk. Blood products and procoagulant factors were administered to most patients at variable levels of hemostatic derangement, and bleeding complications were more common than thrombotic complications. This epidemiologic information and practice variability provide baseline data for the design and powering of interventional studies.
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ItemContinuous renal replacement therapy and its impact on hyperammonaemia in acute liver failure(AUSTRALASIAN MED PUBL CO LTD, 2020-06)OBJECTIVE: Hyperammonaemia contributes to complications in acute liver failure (ALF) and may be treated with continuous renal replacement therapy (CRRT), but current practice is poorly understood. DESIGN: We retrospectively analysed data for baseline characteristics, ammonia concentration, CRRT use, and outcomes in a cohort of Australian and New Zealand patients with ALF. SETTING: All liver transplant ICUs across Australia and New Zealand. PARTICIPANTS: Sixty-two patients with ALF. MAIN OUTCOME MEASURES: Impact of CRRT on hyperammonaemia and patient outcomes. RESULTS: We studied 62 patients with ALF. The median initial (first 24 h) peak ammonia was 132 μmol/L (interquartile range [IQR], 91-172), median creatinine was 165 μmol/L (IQR, 92-263) and median urea was 6.9 mmol/L (IQR, 3.1-12.0). Most patients (43/62, 69%) received CRRT within a median of 6 hours (IQR, 2-12) of ICU admission. At CRRT commencement, three-quarters of such patients did not have Stage 3 acute kidney injury (AKI): ten patients (23%) had no KDIGO creatinine criteria for AKI, 12 (28%) only had Stage 1, and ten patients (23%) had Stage 2 AKI. Compared with non-CRRT patients, those treated with CRRT had higher ammonia concentrations (median, 141 μmol/L [IQR, 102-198] v 91 μmol/L [IQR, 54-115]; P = 0.02), but a nadir Day 1 pH of only 7.25 (standard deviation, 0.16). Prevention of extreme hyperammonaemia (> 140 μmol/L) after Day 1 was achieved in 36 of CRRT-treated patients (84%) and was associated with transplant-free survival (55% v 13%; P = 0.05). CONCLUSION: In Australian and New Zealand patients with ALF, CRRT is typically started early, before Stage 3 AKI or severe acidaemia, and in the presence hyperammonaemia. In these more severely ill patients, CRRT use was associated with prevention of extreme hyperammonaemia, which in turn, was associated with increased transplant-free survival.
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ItemNo Preview AvailableGender differences in mortality and quality of life after septic shock: A post-hoc analysis of the ARISE study(W B SAUNDERS CO-ELSEVIER INC, 2020-02)PURPOSE: To assess the impact of gender and pre-menopausal state on short- and long-term outcomes in patients with septic shock. MATERIAL AND METHODS: Cohort study of the Australasian Resuscitation in Sepsis Evaluation (ARISE) trial, an international randomized controlled trial comparing early goal-directed therapy (EGDT) to usual care in patients with early septic shock, conducted between October 2008 and April 2014. The primary exposure in this analysis was legal gender and the secondary exposure was pre-menopausal state defined by chronological age (≤ 50 years). RESULTS: 641 (40.3%) of all 1591 ARISE trial participants in the intention-to-treat population were females and overall, 337 (21.2%) (146 females) patients were 50 years of age or younger. After risk-adjustment, we could not identify any survival benefit for female patients at day 90 in the younger (≤50 years) (adjusted Odds Ratio (aOR): 0.91 (0.46-1.89), p = .85) nor in the older (>50 years) age-group (aOR: 1.10 (0.81-1.49), p = .56). Similarly, there was no gender-difference in ICU, hospital, 1-year mortality nor quality of life measures. CONCLUSIONS: This post-hoc analysis of a large multi-center trial in early septic shock has shown no short- or long-term survival effect for women overall as well as in the pre-menopausal age-group.
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ItemRisk factors for major adverse kidney events in the first year after acute kidney injury(OXFORD UNIV PRESS, 2021-02)BACKGROUND: Acute kidney injury (AKI) survivors are at increased risk of major adverse kidney events (MAKEs), including chronic kidney disease (CKD), end-stage kidney disease (ESKD) and death. High-risk AKI patients may benefit from specialist follow-up, but factors associated with increased risk have not been reported. METHODS: We conducted a retrospective study of AKI patients admitted to a single centre between 2012 and 2016 who had a baseline estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m2 and were alive and independent of renal replacement therapy (RRT) at 30 days following discharge. AKI was identified using International Classification of Diseases, Tenth Revision codes and staged according to the Kidney Disease: Improving Global Outcomes criteria. Patients were excluded if they were kidney transplant recipients or if AKI was attributed to intrinsic kidney disease. We performed Cox regression models to examine MAKEs in the first year, defined as the composite of CKD (sustained 25% drop in eGFR), ESKD (requirement for chronic RRT or sustained eGFR <15 mL/min/1.73 m2) or death. We examined secondary outcomes (CKD, ESKD and death) using Cox and competing risk regression analyses. RESULTS: We studied 2101 patients (mean ± SD age 69 ± 15 years, baseline eGFR 72 ± 23 mL/min/1.73 m2). Of these, 767 patients (37%) developed at least one MAKE (429 patients developed CKD, 21 patients developed ESKD, 375 patients died). MAKEs occurred more frequently with older age [hazard ratio (HR) 1.16 per decade, 95% confidence interval (CI) 1.10-1.24], greater severity of AKI (Stage 2 HR 1.38, 95% CI 1.16-1.64; Stage 3 HR 1.62, 95% CI 1.31-2.01), higher serum creatinine at discharge (HR 1.04 per 10 µmol/L, 95% CI 1.03-1.06), chronic heart failure (HR 1.41, 95% CI 1.19-1.67), liver disease (HR 1.68, 95% CI 1.39-2.03) and malignancy (non-metastatic HR 1.44, 95% CI 1.14-1.82; metastatic HR 2.26, 95% CI 1.80-2.83). Traditional risk factors (e.g. diabetes and cardiovascular disease) had limited predictive value. CONCLUSIONS: More than a third of AKI patients develop MAKEs within the first year. Clinical variables available at the time of discharge can help identify patients at increased risk of such events.
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ItemA Post Hoc Analysis of Osmotherapy Use in the Erythropoietin in Traumatic Brain Injury Study-Associations With Acute Kidney Injury and Mortality(LIPPINCOTT WILLIAMS & WILKINS, 2021-04)OBJECTIVES: Mannitol and hypertonic saline are used to treat raised intracerebral pressure in patients with traumatic brain injury, but their possible effects on kidney function and mortality are unknown. DESIGN: A post hoc analysis of the erythropoietin trial in traumatic brain injury (ClinicalTrials.gov NCT00987454) including daily data on mannitol and hypertonic saline use. SETTING: Twenty-nine university-affiliated teaching hospitals in seven countries. PATIENTS: A total of 568 patients treated in the ICU for 48 hours without acute kidney injury of whom 43 (7%) received mannitol and 170 (29%) hypertonic saline. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We categorized acute kidney injury stage according to the Kidney Disease Improving Global Outcome classification and defined acute kidney injury as any Kidney Disease Improving Global Outcome stage-based changes from the admission creatinine. We tested associations between early (first 2 d) mannitol and hypertonic saline and time to acute kidney injury up to ICU discharge and death up to 180 days with Cox regression analysis. Subsequently, acute kidney injury developed more often in patients receiving mannitol (35% vs 10%; p < 0.001) and hypertonic saline (23% vs 10%; p < 0.001). On competing risk analysis including factors associated with acute kidney injury, mannitol (hazard ratio, 2.3; 95% CI, 1.2-4.3; p = 0.01), but not hypertonic saline (hazard ratio, 1.6; 95% CI, 0.9-2.8; p = 0.08), was independently associated with time to acute kidney injury. In a Cox model for predicting time to death, both the use of mannitol (hazard ratio, 2.1; 95% CI, 1.1-4.1; p = 0.03) and hypertonic saline (hazard ratio, 1.8; 95% CI, 1.02-3.2; p = 0.04) were associated with time to death. CONCLUSIONS: In this post hoc analysis of a randomized controlled trial, the early use of mannitol, but not hypertonic saline, was independently associated with an increase in acute kidney injury. Our findings suggest the need to further evaluate the use and choice of osmotherapy in traumatic brain injury.
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ItemNo Preview AvailableLong-term Survival of Critically Ill Patients Stratified According to Pandemic Triage Categories A Retrospective Cohort Study(ELSEVIER, 2021-08)BACKGROUND: The COVID-19 pandemic has led to unprecedented demand for ICUs, with the need to triage admissions along with the development of ICU triage criteria. However, how these criteria relate to outcomes in patients already admitted to the ICU is unknown, as is the incremental ICU capacity that triage of these patients might create given existing admission practices. RESEARCH QUESTION: What is the short- and long-term survival of low- vs high-priority patients for ICU admission according to current pandemic triage criteria? STUDY DESIGN AND METHODS: This study analyzed prospectively collected registry data (2007-2018) in 23 ICUs in Victoria, Australia, with probabilistic linkage with death registries. After excluding elective surgery, admissions were stratified according to existing ICU triage protocol prioritization as low (age ≥ 85 years, or severe chronic illness, or Sequential Organ Failure Assessment [SOFA] score = 0 or ≥ 12), medium (SOFA score = 8-11) or high (SOFA score = 1-7) priority. The primary outcome was long-term survival. Secondary outcomes were in-hospital mortality, ICU length of stay (LOS) and bed-day usage. RESULTS: This study examined 126,687 ICU admissions. After 5 years of follow-up, 1,093 of 3,296 (33%; 95% CI, 32-34) of "low-priority" patients aged ≥ 85 years or with severe chronic illness and 86 of 332 (26%; 95% CI, 24-28) with a SOFA score ≥ 12 were still alive. Sixty-three of 290 (22%; 95% CI, 17-27) of patients in these groups followed up for 10 years were still alive. Together, low-priority patients accounted for 27% of all ICU bed-days and had lower in-hospital mortality (22%) than the high-priority patients (28%). Among nonsurvivors, low-priority admissions had shorter ICU LOS than medium- or high-priority admissions. INTERPRETATION: Current SOFA score or age or severe comorbidity-based ICU pandemic triage protocols exclude patients with a close to 80% hospital survival, a > 30% five-year survival, and 27% of ICU bed-day use. These findings imply the need for stronger evidence-based ICU triage protocols.
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ItemEffect of Vitamin C, Hydrocortisone, and Thiamine vs Hydrocortisone Alone on Time Alive and Free of Vasopressor Support Among Patients With Septic Shock The VITAMINS Randomized Clinical Trial(AMER MEDICAL ASSOC, 2020-02-04)IMPORTANCE: It is unclear whether vitamin C, hydrocortisone, and thiamine are more effective than hydrocortisone alone in expediting resolution of septic shock. OBJECTIVE: To determine whether the combination of vitamin C, hydrocortisone, and thiamine, compared with hydrocortisone alone, improves the duration of time alive and free of vasopressor administration in patients with septic shock. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, open-label, randomized clinical trial conducted in 10 intensive care units in Australia, New Zealand, and Brazil that recruited 216 patients fulfilling the Sepsis-3 definition of septic shock. The first patient was enrolled on May 8, 2018, and the last on July 9, 2019. The final date of follow-up was October 6, 2019. INTERVENTIONS: Patients were randomized to the intervention group (n = 109), consisting of intravenous vitamin C (1.5 g every 6 hours), hydrocortisone (50 mg every 6 hours), and thiamine (200 mg every 12 hours), or to the control group (n = 107), consisting of intravenous hydrocortisone (50 mg every 6 hours) alone until shock resolution or up to 10 days. MAIN OUTCOMES AND MEASURES: The primary trial outcome was duration of time alive and free of vasopressor administration up to day 7. Ten secondary outcomes were prespecified, including 90-day mortality. RESULTS: Among 216 patients who were randomized, 211 provided consent and completed the primary outcome measurement (mean age, 61.7 years [SD, 15.0]; 133 men [63%]). Time alive and vasopressor free up to day 7 was 122.1 hours (interquartile range [IQR], 76.3-145.4 hours) in the intervention group and 124.6 hours (IQR, 82.1-147.0 hours) in the control group; the median of all paired differences was -0.6 hours (95% CI, -8.3 to 7.2 hours; P = .83). Of 10 prespecified secondary outcomes, 9 showed no statistically significant difference. Ninety-day mortality was 30/105 (28.6%) in the intervention group and 25/102 (24.5%) in the control group (hazard ratio, 1.18; 95% CI, 0.69-2.00). No serious adverse events were reported. CONCLUSIONS AND RELEVANCE: In patients with septic shock, treatment with intravenous vitamin C, hydrocortisone, and thiamine, compared with intravenous hydrocortisone alone, did not significantly improve the duration of time alive and free of vasopressor administration over 7 days. The finding suggests that treatment with intravenous vitamin C, hydrocortisone, and thiamine does not lead to a more rapid resolution of septic shock compared with intravenous hydrocortisone alone. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03333278.
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ItemConservative Oxygen Therapy during Mechanical Ventilation in the ICU(MASSACHUSETTS MEDICAL SOC, 2020-03-12)BACKGROUND: Patients who are undergoing mechanical ventilation in the intensive care unit (ICU) often receive a high fraction of inspired oxygen (Fio2) and have a high arterial oxygen tension. The conservative use of oxygen may reduce oxygen exposure, diminish lung and systemic oxidative injury, and thereby increase the number of ventilator-free days (days alive and free from mechanical ventilation). METHODS: We randomly assigned 1000 adult patients who were anticipated to require mechanical ventilation beyond the day after recruitment in the ICU to receive conservative or usual oxygen therapy. In the two groups, the default lower limit for oxygen saturation as measured by pulse oximetry (Spo2) was 90%. In the conservative-oxygen group, the upper limit of the Spo2 alarm was set to sound when the level reached 97%, and the Fio2 was decreased to 0.21 if the Spo2 was above the acceptable lower limit. In the usual-oxygen group, there were no specific measures limiting the Fio2 or the Spo2. The primary outcome was the number of ventilator-free days from randomization until day 28. RESULTS: The number of ventilator-free days did not differ significantly between the conservative-oxygen group and the usual-oxygen group, with a median duration of 21.3 days (interquartile range, 0 to 26.3) and 22.1 days (interquartile range, 0 to 26.2), respectively, for an absolute difference of -0.3 days (95% confidence interval [CI], -2.1 to 1.6; P = 0.80). The conservative-oxygen group spent more time in the ICU with an Fio2 of 0.21 than the usual-oxygen group, with a median duration of 29 hours (interquartile range, 5 to 78) and 1 hour (interquartile range, 0 to 17), respectively (absolute difference, 28 hours; 95% CI, 22 to 34); the conservative-oxygen group spent less time with an Spo2 exceeding 96%, with a duration of 27 hours (interquartile range, 11 to 63.5) and 49 hours (interquartile range, 22 to 112), respectively (absolute difference, 22 hours; 95% CI, 14 to 30). At 180 days, mortality was 35.7% in the conservative-oxygen group and 34.5% in the usual-oxygen group, for an unadjusted odds ratio of 1.05 (95% CI, 0.81 to 1.37). CONCLUSIONS: In adults undergoing mechanical ventilation in the ICU, the use of conservative oxygen therapy, as compared with usual oxygen therapy, did not significantly affect the number of ventilator-free days. (Funded by the Health Research Council of New Zealand; ICU-ROX Australian and New Zealand Clinical Trials Registry number, ACTRN12615000957594.).
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ItemNo Preview AvailableFrailty and outcomes from pneumonia in critical illness: a population-based cohort study(ELSEVIER SCI LTD, 2020-11-01)Background A threshold Clinical Frailty Scale (CFS) of 5 (indicating mild frailty) has been proposed to guide ICU admission for UK patients with coronavirus disease 2019 (COVID-19) pneumonia. However, the impact of frailty on mortality with (non-COVID-19) pneumonia in critical illness is unknown. We examined the triage utility of the CFS in patients with pneumonia requiring ICU. Methods We conducted a retrospective cohort study of adult patients admitted with pneumonia to 170 ICUs in Australia and New Zealand from January 1, 2018 to September 31, 2019. We classified patients as: non-frail (CFS 1–4) frail (CFS 5–8), mild/moderately frail (CFS 5–6),and severe/very severely frail (CFS 7–8). We evaluated mortality (primary outcome) adjusting for site, age, sex, mechanical ventilation, pneumonia type and illness severity. We also compared the proportion of ICU bed-days occupied between frailty categories. Results 1852/5607 (33%) patients were classified as frail, including1291/3056 (42%) of patients aged >65 yr, who would potentially be excluded from ICU admission under UK-based COVID-19 triage guidelines. Only severe/very severe frailty scores were associated with mortality (adjusted odds ratio [aOR] for CFS=7: 3.2; 95% confidence interval [CI]: 1.3–7.8; CFS=8 [aOR: 7.2; 95% CI: 2.6–20.0]). These patients accounted for 7% of ICU bed days. Vulnerability (CFS=4) and mild frailty (CFS=5) were associated with a similar mortality risk (CFS=4 [OR: 1.6; 95% CI: 0.7–3.8]; CFS=5 [OR: 1.6; 95% CI: 0.7–3.9]). Conclusions Patients with severe and very severe frailty account for relatively few ICU bed days as a result of pneumonia, whilst adjusted mortality analysis indicated little difference in risk between patients in vulnerable, mild, and moderate frailty categories. These data do not support CFS ≥5 to guide ICU admission for pneumonia.
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ItemNo Preview AvailableConservative oxygen therapy for mechanically ventilated adults with suspected hypoxic ischaemic encephalopathy(SPRINGER, 2020-12)PURPOSE: Liberal use of oxygen may contribute to secondary brain injury in patients with hypoxic-ischaemic encephalopathy (HIE). However, there are limited data on the effect of different oxygen regimens on survival and neurological disability in HIE patients. METHODS: We undertook a post-hoc analysis of the 166 patients with suspected HIE enrolled in a trial comparing conservative oxygen therapy with usual oxygen therapy in 1000 mechanically ventilated ICU patients. The primary endpoint for the current analysis was death or unfavourable neurological outcome at day 180. Key secondary outcomes were day 180 mortality, and cause-specific mortality. RESULTS: Patients with HIE allocated to conservative oxygen spent less time in the ICU with an SpO2 ≥ 97% (26 h [interquartile range (IQR) 13-45 vs. 35 h [IQR 19-70], absolute difference, 9 h; 95% CI - 21.4 to 3.4). A total of 43 of 78 patients (55.1%) assigned to conservative oxygen and 49 of 72 patients (68.1%) assigned to usual oxygen died or had an unfavourable neurological outcome at day 180; odds ratio 0.58; 95% CI 0.3-1.12; P = 0.1 adjusted odds ratio 0.54; 95% CI 0.23-1.26; P = 0.15. A total of 37 of 86 patients (43%) assigned to conservative oxygen and 46 of 78 (59%) assigned to usual oxygen had died by day 180; odds ratio 0.53; 95% CI 0.28-0.98; P = 0.04; adjusted odds ratio 0.56; 95% CI 0.25-1.23; P = 0.15. Cause-specific mortality was similar by treatment group. CONCLUSIONS: Conservative oxygen therapy was not associated with a statistically significant reduction in death or unfavourable neurological outcomes at day 180. The potential for important benefit or harm from conservative oxygen therapy in HIE patients is not excluded by these data.